This invention relates to a carrier converter, such as an FM-to-AM converter.
Various FM-to-AM converters are already in use for converting input FM (frequency modulated) signals directly to output AM (amplitude modulated) signals. A coventional FM-to-AM converter, however, has disadvantages as will later be described with reference to some figures of the accompanying drawing. For example, the carrier frequency of the output AM signal has to be selected in consideration of the frequency of the input FM signal. The amplitude of the AM signal has not been in excellent linear relation to the frequency shifts or deviations of the FM signal. Furthermore, the amplitude has been dependent on fluctuation in the amplitude of the FM signal so that use of an amplitude limiter of excellent performance has been indispensible in prior AM-FM converters. In a conventional FM-to-AM or AM-to-FM converters, it has been mandatory, although objectionable in view of FM-to-AM or AM-to-AM conversion characteristics of the carrier converter, to use rejection filters or traps on both input and output sides, respectively.